Question

Write an equation in point-slope form and in slope-intercept form.

Answer 1

The point-slope form:

$y-y_1=m(x-x_1)\\\\m=\dfrac{y_2-y_1}{x_2-x_1}$

We have the points (1, -5) and (-3, 7). Substitute:

$m=\dfrac{7-(-5)}{-3-1}=\dfrac{12}{-4}=-3\\\\y-(-5)=-3(x-1)\\\\\boxed{y+5=-3(x-1)}$

The slope-intercept form:

$y=mx+b$

$y+5=-3(x-1)$           use distributive property

$y+5=-3x+3$             subtract 5 from both sides

$\boxed{y=-3x-2}$